Method of punching.



B. E. BOSLER. METHOD OF PUNOHING. APPLICATION FILED 1mm 22. 1909.

Patented Oct. 8, 1912.

INVENTOR.

BENJAMIN E. IBOSLER, OF JOHNSTOWN, PENNSYLVANIA.

FFIC.

\ METHOD OF PUNCHING.

To all whom it mag concern Be-it known that I, BENJAMIN E. Bosnen, a citizen of the United States, residingin the city of Johnstown, in the county of Cambria and State of Pennsylvania, have invented certain new and useful Improvements in Methods of Punching; audI do hereby declare the following to be-a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to methods of punching bolt-holes in metal, especially in splicebars having curved outer surfaces.

Since the bearing surfaces of ordinary bolt-heads or nuts are flat, they will not seat properly on the curved surface of a splice-bar, particularly when this surface is concave as is often the case. I provide a flat bearing surface for the bolt-head or nut by forming a countersunk portion around the bolt-holes on the outer side of the bar. In some cases I also form reinforcing bosses on the inner side of the bar opposite each countersunk portion, using for this purpose the metal displaced in the operation of countersinking.

Referring to the sheet of drawings ac-' companying this specification, in which like characters of reference indicate like parts throughout the views :-Figure 1 is a cross section through the lower part of a punching apparatus showing, in position, a punch and die suitable for carrying out the first stage of my method of punching, the punch being shown in elevation; Fig. 2 is a similar view showing, in position, a punch and die suitable for carrying out the final stage of my method; Fig. 3 is a perspective view of part of a splice-bar which has been subjected to the first stage; and Fig. 4 is a perspective view of part of a completed splice-bar. Fig. 5 is a perspective view of the inside portion of a splice-bar showing the re-inforcin bosses which are pressed up out of the solid metal on the sides and also allow for the displacement of the metal by the countersinking of the other side.

Referring now to the drawings in detail, 1 represents the clamping-die, which is used to hold the splice-bar firmly in position and prevent distortion during the punching operations. It is shaped to conform to the surface of the splice-bar and is operated by suitable means not shown.

The punch- Speciflcation of Letters Patent.

stocks 2 are here shown as separate from the punches although both may of course be in one piece.

The punch 3 in Fig. 1 is used in forming the countersunk portions 4 on the splicebar and is used in connection with the die 5. This die 5 is shaped to conform to the surface of the splice-bar and is preferably made without a hole in it so that it can act as an anvil. The distortion of the bar is prevented by pressure between the clamping-die and the die-block 6, both of which are shaped to conform to the surfaces with which they are in contact. Whenever I desire to form reinforcing bosses on the bar opposite the indentations, I use a die having recesses in its uppersurface as shown in dotted lines in Fig. 2 to permit the metal displaced by the punch 3 to bulge out at these points. The re-inforcing bosses are marked 11 in Fig. 5. The surface of the end of punch 3 1s,flat, preferably with slightly rounded corners, and the movement of the punch is such as to cause this fiat end to indent the surface of the splice-bar.

The punch 7 and die 8 shown in Fig. 2 are used in punching the holes 9 through the countersunk portions 4 of the splice-bar. The cap 10 for securing the punch 7 to the punch-stock may be of the same size as punch 3 or it may, be somewhat smaller as shown in dotted lines in Fig. 2 so as not to touch the splice-bar.

My method of operation is as follows Placing the splice-bar in position as shown in Fig. 1, and usinga punch and die similar to those shown in this figure, I indent the upper surface metal being forced aside along the line 0 least resistance. During this operation the clamping-die is pressed forcibly against the splice-bar. The final stage in the operation consists in punching holes through the countersunk portions just formed. For this purpose the punch and die shown in Fig. 2 may be used, the die being similar in shape to that used in the previous operation except that now a hole in the die is essential.

Although I have shown and described my improvements in considerable detail, I do not wish to be limited to the exact and specific details shown and described, but may use such substitutions, modifications or equivalents thereof, as are embraced within the scope of my invention. or as pointed out in the claims.

of the bar, the displaced Patented Oct. 8, 1912. Application filed June 22, 1909. Serial No. 503,593.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. The method of punching bolt-holes in a splice bar which consists in clamping said bar between a pair of dies adapted to conform to and prevent distortion of the railbearing surfaces of said bar, then indenting hflat countersink portions in the outer surface of the bar by pressure sufiicient to cause flow, and extrusion of solid metal from other portions of said bar, and then punching holes through said countersunk portion 2. The method of punching bolt-holes in a splice-bar, which consists in clamping said signature in the presence of two Witnesses. I

BENJAMIN E. BOSLER.

Witnesses:

WM. J. F rrzMAUmoE, J12, MER SEAVEY. 

